There's not a lot of green in the urban jungle of Sao Paulo, but thanks to Fernanda Danelon, restaurants in the Brazilian mega-city are turning their waste back into food at innovative gardens tucked amid the skyscrapers.

Danelon, a 43-year-old journalist by training, quit her day job two years ago to launch the Guandu Institute, which recycles restaurants' food waste and helps them set up gardens to put all that compost to good use.

Cities in Brazil, the economic giant of Latin America, throw out more than 75 million tons of trash a year, according to the Brazilian Association of Public Sanitation Companies (ABRELPE).

About half of it is organic waste, according to the Brazilian environment ministry.

There are no municipal recycling or composting programs to reduce all that garbage, and triaging trash is a foreign concept to most Brazilians.

The country recycles about three percent of its waste, according to ABRELPE.

To fill the void, Danelon decided to put her passion for composting and gardening to work on behalf of restaurants in her hometown.

Her organization collects restaurants' food waste at their doors, turns them into compost over the course of three to four months, and delivers the compost back to the restaurants to fertilize in-house gardens -- which the institute also helps them set up and maintain.

She started with just one restaurant. Today, she has 17, and is in talks with 10 more.

"At first, I collected the trash myself in my car," Danelon said with a laugh as she turned over dirt with a shovel in the leafy courtyard of her house in Sao Paulo.

"But now we've grown, and today we recycle 30 to 40 tons of organic waste per month."

- Gardens in the sky -

Her partners include French restaurant Le Bilboquet, in the chic downtown neighborhood of Jardins.

With Danelon's help, the restaurant now has cherry tomatoes, lemons and lavender plants growing on its rooftop, a stone's throw from the skyscrapers of the Brazilian economic capital's financial district.

Its French chef, 34-year-old Julien Mercier, signed up for Danelon's program six months ago.

"What we grow here isn't enough to supply the whole restaurant. But the important thing is to understand that we're part of a process. These things are growing here, and we can also boast that we recycle a ton and a half of organic waste every month," he told AFP as he inspected his vegetables and herbs.

The waste is composted at a facility about 50 kilometers (30 miles) outside the city, where it is mixed with earth and allowed to biodegrade over the course of months.

It is a "traditional composting technique," without enzymes or earthworms to accelerate the process, said Danelon. But with a little patience, all that waste turns into rich, nutrient-packed compost.

- Seeing things differently -

The average 50-table restaurant pays 900 reals ($275) a month for the composting and gardening service -- about the same as the municipal waste collection fee.

"We have to look squarely at our own waste, value it and know that it can be reused," said Danelon.

She offers starter kits for people looking to make their own compost at home. More and more people are contacting her to ask about setting up communal gardens on the roofs of their apartment buildings, she said.

At Mesa III, a deli in a working-class neighborhood, customers are greeted by basil, sage and rosemary plants ever since the Guandu Institute trained the staff.

"If we as a society realize how much trash we're producing, we'll see it's just atrocious," said owner Ana Soares, 63.

Her restaurant has installed a recycling system for glass and switched to cardboard take-out containers to cut down on plastic.

"That's why we joined this beautiful project," she said. "We have to learn to look at things in a new way."